如果在where子句

Question

之間使用if我不知道我應該如何框架我的問題，因爲即使我不知道我究竟要搜索什麼。可能是這個問題最好的地方。我想在where子句中使用If條件，這可以用case來完成，但我的問題是我不想在列名後面使用它，而是希望避免整個執行該列。你可以通過我在上次我評論過的程序來了解它，所以我想實現這樣的事情，因爲我想再次爲這種情況編寫相同的過程，我認爲這可以通過做類似的事情來實現。我在互聯網上搜索我得到的是在哪些地方不符合我的目的。請看最後一行來理解問題。感謝名單

USE [overseascrm] 
GO 
/****** Object: StoredProcedure [dbo].[candidatesearch] Script Date: 05-07-2014 00:48:17 ******/ 
SET ANSI_NULLS ON 
GO 
SET QUOTED_IDENTIFIER ON 
GO 
ALTER procedure [dbo].[candidatesearch] 
@candidate_id varchar(50), 
@firstname varchar(50), 
@lastname varchar(50), 
@emailid_1 varchar(100), 
@mobile_1 varchar(20), 
@from varchar(50), 
@to varchar(50), 
@agentid varchar(50), 
@passportno varchar(50), 
@profession int, 
@isactive bit 
as 

begin 
DECLARE @candidateid_var varchar(50) 
DECLARE @firstname_var varchar(50) 
DECLARE @lastname_var varchar(50) 
DECLARE @emailid1_var varchar(100) 
DECLARE @mobile_1_var varchar(20) 
DECLARE @agentid_var varchar(50) 


IF(@agentid = '') 
begin 
SET @agentid_var = '%' 
END ELSE BEGIN 
SET @agentid_var = @agentid 
END 


IF (@candidate_id = '') BEGIN 
SET @candidateid_var = '%' 
END ELSE BEGIN 
SET @candidateid_var = @candidate_id 
END 

IF (@firstname = '') BEGIN 
SET @firstname_var = '%' 
END ELSE BEGIN 
SET @firstname_var = @firstname 
END 

IF (@lastname = '') BEGIN 
SET @lastname_var = '%' 
END ELSE BEGIN 
SET @lastname_var = @lastname 
END 

IF (@emailid_1 = '') BEGIN 
SET @emailid1_var = '%' 
END ELSE BEGIN 
SET @emailid1_var = @emailid_1 
END 

IF (@mobile_1 = '') BEGIN 
SET @mobile_1_var = '%' 
END ELSE BEGIN 
SET @mobile_1_var = @mobile_1 
END 

IF (@from = '') BEGIN 
SELECT 
    * 
FROM candidate C 
LEFT JOIN candidate_profession_map CM 
    ON C.candidate_id = CM.candidate_id 
LEFT JOIN passport_details PD 
    ON C.candidate_id = PD.candidate_id 
WHERE C.candidate_id LIKE '' + @candidateid_var + '%' 
AND firstname LIKE '' + @firstname_var + '%' 
AND lastname LIKE '' + @lastname_var + '%' 
AND emailid_1 LIKE '' + @emailid1_var + '%' 
AND mobile_1 LIKE '' + @mobile_1_var + '%' 
AND agent_id LIKE '' + @agentid_var + '%' 
AND CM.profession_id = @profession 
AND C.isactive = @isactive 
AND PD.passport_no = @passportno 
END ELSE BEGIN 
SELECT 
    * 
FROM candidate C 
LEFT JOIN candidate_profession_map CM 
    ON C.candidate_id = CM.candidate_id 
LEFT JOIN passport_details PD 
    ON C.candidate_id = PD.candidate_id 
WHERE C.candidate_id LIKE '' + @candidateid_var + '%' 
AND firstname LIKE '' + @firstname_var + '%' 
AND lastname LIKE '' + @lastname_var + '%' 
AND emailid_1 LIKE '' + @emailid1_var + '%' 
AND mobile_1 LIKE '' + @mobile_1_var + '%' 
AND agent_id LIKE '' + @agentid_var + '%' 
AND C.addedon BETWEEN CONVERT(DATETIME, @from, 103) AND CONVERT(DATETIME, @to, 103) 
--IF (@profession <> 0)BEGIN 
--AND CM.profession_id = @profession 
--END 
AND C.isactive = @isactive 
OR PD.passport_no = @passportno 
END 

END 

Answer 1

你可以使用，你創建你的SELECT語句爲varchar根據自己的喜好動態SQL執行，使用sp_executesql在最後執行它

http://msdn.microsoft.com/en-us/library/ms188001.aspx

Answer 2

ALTER procedure [dbo].[candidatesearch] 
    @candidate_id varchar(50), 
    @firstname varchar(50), 
    @lastname varchar(50), 
    @emailid_1 varchar(100), 
    @mobile_1 varchar(20), 
    @from varchar(50), 
    @to varchar(50), 
    @agentid varchar(50), 
    @passportno varchar(50), 
    @profession int, 
    @isactive bit 
AS Begin 

    SELECT * 
    FROM candidate C 
    LEFT JOIN candidate_profession_map CM ON C.candidate_id = CM.candidate_id 
    LEFT JOIN passport_details PD ON C.candidate_id = PD.candidate_id 
    WHERE (@candidateid='' or C.candidate_id LIKE @candidateid + '%') 
    AND (@firstname = '' or firstname LIKE @firstname + '%') 
    AND (@lastname = '' or lastname LIKE @lastname + '%') 
    AND (@emailid_1='' or emailid_1 LIKE @emailid1 + '%') 
    AND (@mobile_1 = '' or mobile_1 LIKE @mobile_1 + '%') 
    AND (@agentid='' agent_id LIKE @agentid + '%') 
    AND C.isactive = @isactive 
    And ((@from='' 
       AND CM.profession_id = @profession 
       AND PD.passport_no = @passportno) 
     or (@from<>'' 
       And C.addedon BETWEEN CONVERT(DATETIME, @from, 103) AND CONVERT(DATETIME, @to, 103) 
       OR PD.passport_no = @passportno) 

End